Selection to turn data entered into a negative value

[1starr]

I have a form that has a drop down box where the customer can select an item. I have three items which if select I want it to turn data enter into the text field into a negative value when the customer inputs their data, but only when they make that selection. I am stumped on how to get this accomplish. Do anyone have a hint or have encountered this situation, please help.

 

[1starr]

I found the solution to this one. In the After Update text box put this code example:
If me.textname.value > 0 then
Select case Me.Dropdwnbox.value
Case "John", "Peter", "Tom"
Me.textname.value = Me.textname.value * -1
Case else
End select
End if

This worked for me and I hope it will be of some help to others.